How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Amedee Your Own Question
Amedee, VW Technician
Category: VW
Satisfied Customers: 24146
Experience:  ASE certified Technician advanced level specialist. Wisconsin certified emissions state inspector
Type Your VW Question Here...
Amedee is online now
A new question is answered every 9 seconds

2002 VW Beetle: oxygen sensor or something..catalytic

Resolved Question:

I have another code on my 2002 VW Beetle. It's P0420. Guy at Auto Zone's computer said it was either an oxygen sensor or something with the catalytic system. Is there any way to tell the difference? I know that replaced an oxygen sensor shortly after I bought the car so that would be June of 2008.
Submitted: 5 years ago.
Category: VW
Expert:  Amedee replied 5 years ago.
Hello and Welcome to Just Answer. My name is XXXXX XXXXX I will try my best to assist you and your 100% satisfaction is my goal. I have been working on these vehicles for over 10 years so I am very familiar with this system and how it works. However, keep in mind, that I need some solid concrete facts/evidence from you in order to give you a good answer about your vehicle. Please realize that all my answers are based solely on the info that you provide me with....

Have you replaced any part yet for this code?

How does your engine run?

Customer: replied 5 years ago.
I haven't touched anything for this code yet. It has lost maybe two or three mpg. After I start it if I let it idle more than about 5 minutes, it slightly shutters a bit. With everything I've had to replace on it in the last year, I'm about at the end of my rope. Rack & pinion, coil packs, battery AND alternator.
Expert:  Amedee replied 5 years ago.
WHat size engine do you have?
Customer: replied 5 years ago.
4 cylinder, know for sure not a turbo. Bought used so it didn't come with an owner's manual. OH! And plugs & wires were done December 2009. Somebody already suggested those.
Expert:  Amedee replied 5 years ago.
This is a converter code.

Test the catalyst inlet and outlet temperature after a long test-drive. The outlet temperature of the catalyst should be about 150 degrees Fahrenheit hotter than the inlet temperature. Check for and verify that no un-metered air is reaching the catalyst (vacuum leaks, leaking exhaust). If the o2 senors are working good, then the converter is at fault causing your problem.

Potential Causes:
Defective Catalyst
Oxygen (O2) Sensors
Customer: replied 5 years ago.
So is this something that the guys next door to me can do or do I need to take it back to the VW dealer, who I am nto happy with at the moment after they screwed up fixing my hood release. And if I do go to a shop, what am I looking at cost wise?
Expert:  Amedee replied 5 years ago.
The converter calls for about 1.5 hours labor to replace. I don't know the cost of your converter, but I would not be surprised if it is close to 500 or 600 bucks.

Dont use after market stuff. Get a dealer cat.

I DO hope you found my Answer to be helpful regarding your vehicles condition. IF SO-please hit **ACCEPT** as you read this Answer, in order that I may receive credit for my time, thanks. BONUSES & Positive Feedback Most appreciated!

Please Note: I receive ZERO Credit until & unless you choose to ACCEPT my well thought-out Answer.


Amedee and other VW Specialists are ready to help you